“Whereas there may be a place for some 20mph limits, blanket zones will compromise road safety. Drivers must legally take due care over other road users and adjust speed to the conditions. Professor Wann of Royal Holloway College has warned against blanket zones, as drivers become less likely to comply.

Scarce funds would be better spent on measures that will actually make roads safer, such as eradicating potholes, which benefits cyclists, too.

20mph zones are sometimes justified because pedestrians hit at a lower speed are more likely to survive. However it would be better to educate them in proper road safety, particularly in using designated crossing places, to prevent them being hit at any speed.

If this means parents taking responsibility for their children, and training them not to dash out, then good. The way gratuitous 20mph zones are sold might give a false sense of security to young pedestrians in crossing faster roads; remember that they can still be killed by traffic legally travelling at 20mph.

A culture of mutual respect and consideration between road users can only be a good thing. Having drivers’ eyes glued to their speedos rather than the road ahead is not.”

~ Brian Mooney, Alliance of British Drivers ~

“I wish you to note my objection to the proposed 20 mph limit in Worthing. Having lived in Worthing all my life and being an Observer Instructor for both the Worthing Advanced Motorists and Sussex RoSPA Advanced Motorists, I am well acquainted with the area and the prevailing traffic conditions.

Now anyone in favour of the reduced limit will try to twist this and assume that I am quite happy about the number of injuries on our streets and that nothing is worth considering to improve the status quo. Not so.

The appropriate speed in any situation will vary as surely as night follows day and in Worthing there would be many a situation when 20 mph would be excessive, but conditions change by the second, and are the majority of motorists so dim that they are unable to respond to this without instruction by the law? I don’t think so.

Driving at lower speeds necessitates lower gears creating more pollution as well as driver frustration, safer driving is achieved by concentration, planning ahead and the further driver training which the above organizations offer to the general public.“

~ John Hews, Worthing Advanced Motorists & Sussex RoSPA ~

“The RAC is not in favour of blanket 20mph speed limits, but there is evidence that 20mph limits are beneficial in accident hot spots, in busy urban areas and near schools. Our members broadly support these zones and accept more are needed. We feel motorists should always drive within the limit but at a speed which is appropriate to where they are and for the road and weather conditions at the time. In many 30mph zones it would be inappropriate to encourage motorists to drive at 20mph unless the conditions and the traffic levels warranted it.”

~ The RAC ~

“Support for blanket 20mph limits isn’t as universal as campaigners claim. I am traffic management adviser for the Alliance of British Drivers, and a retired highway, traffic and road safety engineer with over 30 years` local authority experience.

The campaign group 20’s Plenty for Us issued a press release last month to mark the publication of a briefing note by the Local Government Information Unit (LGiU), entitled Area-wide 20mph neighbourhoods: a win, win, win for local authorities. Subsequently, Anna Semlyen, 20’s Plenty’s campaigns manager, wrote in Local Transport Today (LTT) in favour of making 20mph the national speed limit in street-lit areas (LTT 19 Dec 13).

Clearly, the proponents of blanket 20mph speed limits are trying to create the impression that the evidence is overwhelmingly in their favour and the momentum for a reduction in the urban speed limit is unstoppable. This must not be allowed to go unchallenged.

The title of the LGiU briefing note suggests a very one-sided analysis and this is confirmed when reading it. While 20’s Plenty describes the report as “independent”, it contains frequent references to 20’s Plenty for Us and other organisations unsympathetic to motor vehicle users.

The report makes much of the claimed benefits of 20mph limits in terms of public health, safety etc, but makes virtually no mention of the impact on drivers. The author clearly does not understand the correct use of speed limits or how drivers vary their speed according to changing conditions, which is an intuitive and non-numeric process. This is why reductions in speed limit produce a far lower impact on driven speeds (typically around 1mph where 30mph limits are reduced to 20mph).

Some of the claims in the LGiU report are very shaky. One, from Bristol City Council, states that walking and cycling increased on average by 23 and 20.5% respectively after 20mph limits were introduced. Results elsewhere have shown very little change in walking or cycling in 20mph areas, so I investigated the Bristol figures and discovered they came from a council report in July 2012. That report states that walking increased by between 10 and 36%, and cycling by between 4 and 37%. So the claimed average increases were calculated by adding the highest and lowest percentages and dividing by two! Such an appalling misuse of statistics does not inspire confidence.

Another dubious claim is from a 2011 British Social Attitudes Survey, in which 73% of those surveyed were said to favour 20mph limits for residential roads. Several factors could influence this result, not least the wording of the question and respondents’ understanding of ‘residential road’. Most people are unaware that speed limit reductions achieve a much lower fall in actual speeds, so will have a mistaken view of what a 20mph limit would achieve. There is also the phenomenon of people giving what they think is the ‘virtuous’ answer to an opinion poll.

As any police officer who enforces speed limits will confirm, whenever residents demand a lower limit, among the first to be caught exceeding it will be those who campaigned for it in the first place. People are very ambivalent about speed limits and an opinion poll finding should be taken with a large pinch of salt. It should certainly not be assumed to support a blanket change from 30 to 20mph.

Despite the assertions of 20’s Plenty and others, by no means all local authorities are itching to impose blanket 20mph limits. Indeed, in Anna Semlyen’s own authority of York, Lib Dem councillors oppose area-wide use (LTT 26 Jul 13). Norfolk has rejected them (LTT 4 Oct 13) and so has Kirklees (LTT 19 Dec 13). Even in Green-dominated Brighton, the council’s 20mph ambitions have been curtailed (LTT 19 Dec 13).

It is claimed by 20’s Plenty that changing the default limit to 20mph would halve the cost to councils of imposing the lower limit area-wide. However, this ignores the massive additional cost that would be imposed on those councils that do not wish to follow the 20mph blanket approach. DfT figures on road length suggest there are probably some 70-75,000 miles of urban, street-lit road in England and Wales with the default 30mph limit. Even if half this mileage consists of narrow residential roads where 20mph may be an appropriate limit (unlikely), the cost of re-signing the other half, and all the junctions between 30mph and 20mph roads, would be prohibitive. This is probably what 20’s Plenty is banking on – that most local authorities would roll over and submit to their extreme view. So much for local choice! It must not be allowed to happen; the DfT must remain resolute in retaining the 30mph urban limit.

Where 85th percentile speeds exceed 20mph by a significant margin, lowering the speed limit from 30mph should never be considered. On roads where speeds are already below 20mph, what is achieved by introducing a 20mph limit? Speeds will barely change but a false sense of security may be created, which probably accounts for the increases in some types of casualty seen in many of the schemes already implemented.

The proponents of blanket 20mph limits are invariably found in that part of the political spectrum that promotes regulation of all aspects of everyday life and abhors the freedom of choice that cars provide. The ABD, on the other hand, believes in personal choice and individual responsibility. The success of well designed shared-space schemes shows that road safety can be enhanced when controls and priorities are removed and individual road users are made to think for themselves. This must surely be a better and more acceptable approach than heavy-handed, over-regulation.”

~ Malcolm Heymer, Alliance of British Drivers ~

“20mph zones, areas and limits have been gaining in popularity in recent years but their overall impact on road safety is at best unclear.In the IAM’s view many of these schemes have been introduced with little evaluation of their road safety benefit.

Speed limits must match the road environment or drivers can become confused.Getting the speed limit right leads to self-compliance with little need for expensive enforcement.Good design and widespread consultation is the key.

There is no clear evidence that mandatory limits perform better than advisory ones or even traffic calming features.

The key requirement of any 20mph zone must be that it is self-enforcing either through signposting that makes sense or traffic calming features.Given the low number of deaths and serious injuries on residential roads limited police enforcement resources should be prioritised elsewhere.

Research suggests that drivers use the clues from the built up environment around them to judge the correct speed.In narrow roads with parked cars and pedestrians the vast majority of drivers reduce their speed anyway.Where limits do not match the environment uncertainty and confusion are generated which can raise stress levels and provide an unwelcome distraction from safe driving.This may also lead to a wider disrespect for speed limits.All roads differ in their form and function at a very detailed level and the limit should reflect that.This is why the IAM does not favour a blanket approach to speed limits or a wholesale change in the urban limit from 30 to 20. Distributor roads should remain as 30mph or above with design features to enhance pedestrian and cycling safety.

The evaluation of large scale 20mph area approaches, such as that in Portsmouth, confirms the findings of similar schemes that there are small reductions in speed in the short-term, but little evidence of a reduction in casualties.In Portsmouth there was only an overall average reduction of 1 mph.

The limited safety benefits are not unexpected as in many 20mph areas there was a not a major road safety problem to start with and therefore sharp drops in casualties were an unrealistic expectation.This underlines the importance of independent evaluation without the involvement of local political groups who often overestimate the road safety benefits to push schemes through.Only a truly independent, evidence led and objective analysis of the impact of a scheme can prove the real benefits and disbenefits.”

~ Tanvir Nandra, Institute of Advanced Motorists ~

”Widening the spread of these ‘slowdown zones’ will be counterproductive and create more accidents.What you’ll get is drivers driving to the speedometer. It’s safer that drivers drive to what they’re seeing outside the car and not to what their speed needle is saying.”

Focusing on driving at 20mph – where minute movements of the accelerator can see you exceed the limit easily – could tear your concentration away from the road. It’s important to focus on everything around you, especially in built-up urban areas where slowdown zones are most widely implemented.

Pedestrians stepping out from behind cars, areas around schools and passengers exiting vehicles into the road all pose potential hazards that require your awareness to avoid. It’s argued that fixing your gaze on the speedometer could see more incidents – such as the above – occur in 20mph areas.

There’s also an environmental cost. According to the Highways Agency’s figures, at 30mph average CO2 emissions for vehicles (including 10% Heavy Goods Vehicles) stands at 188g/km, whereas at 20mph this rises to 221g/km. This is usually due to motorists driving in a lower gear than they normally would.

As CO2 output is linked to fuel consumption, it could thus hurt your motoring outgoings by driving at a slower speed.”

“Cutting the speed limit from 30 mph to 20 mph on the wrong roads can increase CO2 emissions by more than 10% with the result that well-intentioned safety schemes may backfire in environmental terms. On average, petrol car fuel consumption on longer and relatively free-flowing 20mph urban streets can worsen by 5.8 miles per gallon (1.3 miles/litre). Over a year this will significantly increase CO2 emissions – burning 1 litre of unleaded petrol produces 2.36kg of CO2.”

~ The AA ~

”The Partnership supports the introduction of targeted and tailored 20mph speed limits where they are justified, and supported by the local community. We don’t, however, support the concept of blanket 20mph speed limits imposed across whole areas without justification”